I am using HY-DIV268N-5A, with minor modifications. All three axis are working well with two NEMA 23 and one NEMA 34 motor. I have run them fast and slow. Not seeing any dropout.
I am using a 25Volt power supply to the NVUM, and 36 volts to the drivers. The 36 volt supply is analog with a large transformer. I also have a 100 UF 63V cap at the top of each driver on the power terminals. With the distributed capacitance not getting much noise. I will try to get an oscilloscope on it this weekend.
tholling55